268 NEW FOSSIL SHELLS 



I can find none of our species of Turbo to which this pretty little shell can be referred. 

 With the same number of whorls, it is hardly more than a fourth the size of the T. 

 caperatus, Con., which it in some degree resembles. And, in our species, the transverse 

 stria? are large, almost deserving the appellation of ribs, while in the T. caperatus they 

 are described as small. 



FAMILY CANALIFERID^]. 



GENUS CERITHIUM. 

 C. CLAVTJLUS, PL. 37. FIG. 89. 



C. testa turrita, valde elevatd, crassd. costatd, striatd; spird acutd, cornea, valde attenuatd, mdmillatd; suturis linea- 



ribus, sub-obsoletis; anfractibus , planis; costis tribus, transversis, magnis, sub-acutis, leevibus; striis longitudina- 



libus, rarisj parvis; anfractu ultimo angulato; basi Icevi; aperlurd quadratd; canali brevi, minimi profundo. 



Shell turrited, very elevated, thick, costate, striate; spire acute, conical, very attenuate, mamillate; sutures linear, 

 almost obsolete; whorls , flat; ribs three, transverse, large, sub-acute, smooth; strise longitudinal, small, infre- 

 quent: last whorl angular; base smooth; mouth quadrate; canal short, shallow. 



Length . Breadth .15 of an inch. 



Remarks. The longitudinal stria?, from their size, although they do not cross the ribs, 

 give the shell a cancellated appearance under the microscope. The mouth is nearly 

 square. The body whorl has four instead of three stria?, a very small one being placed 

 immediately below the angle. 



This species bears a strong resemblance to the C. terebrale,* Adams, a recent shell 

 from our coast, but it may be distinguished by having the transverse ribs fewer and 

 more acute, the longitudinal stria? less frequent and larger, and the canal longer and less 

 profound. It also approaches the Terebra constricta, Nob., but the ribs are more flat- 

 tened, and the stria? less numerous and larger. 



Although not thin, this shell is extremely fragile, as out of about fifty specimens I have 

 not one full-grown one with the apex perfect. It attains a much larger size than that 

 shown in the figure. 



C. CURTUM, PL. 37. FIG. 90. 



C. testa elevato-conica, tenui, sub-cancellatd, carinatd, sub-perforatd; spird breviusculd, acutd, ad apicem Icevi; 

 suturis excavatis; anfractibus sex, medio carinatis; striis transversis et sulcis longitudinalibus variabilibus; ultimo 

 anfractu angulato; basi minute striatd; perforatione minima, aliquando obsoletd; aperturd ovatd, superne angulatd, 

 inferne valde ejffusd. 



Shell elevated conical, thin, sub-cancellate, carinate, sub-perforate; spire rather short, acute, smooth at the apex- 

 sutures excavated ; whorls six, carinate in the middle ; transverse striae and longitudinal sulci variable ; last whorl 

 angular; base minutely striate; perforation very small, sometimes obsolete; mouth ovate, angular above, very effuse 

 below. 



Length .15. Breadth .06 of an inch. 



Remarks. The longitudinal sulci are very variable, being sometimes almost obsolete, 

 while at others they give the shell a completely cancellate appearance, cutting the stria? 



* As the name of this shell has been preoccupied, by Lamarck, for a fossil species from Grignon, I propose that the 

 name of the discoverer be affixed to it, changing it to C. Adamsii. I find also that the name of the C. cancellatum, 

 Nob., has been used by the same author. I. therefore, change it to C. spina. 



